You Got to Be Kidding Me!

Solar Powered UAV

Posted in Aircraft and Flying, Electric Vehicles by Stacy McMahon on August 24, 2008

Another step toward manned electric flight*, mainly because of the lithium-sulfur batteries. It’s interesting to watch people’s thinking get more focused as they actually go out and try to do things. Engineers know all about this, but it’s really nice to have your thinking accelerated by trying out your idea and seeing what happens.

Lithium-Sulfur batteries for night flying

Lithium-Sulfur batteries for night flying

* I know electric planes have flown already, but battery weight is one of the critical problems (much like with electric cars)


Engineering Break: Thoughts on The ME 109 Versus the ‘Spit’

Posted in Aircraft and Flying, Engineering by Stacy McMahon on June 5, 2007

One of my very minor hobbies is reading “period” pilot reports about WW2 fighter planes. The other day I Googled up a dour and uncomplimentary review of the Messerschmitt 109, written by Kit Carson for Airpower Magazine in the mid-70s, and based on some apparently incomplete and selectively reported data from wartime reports page. Shortly after, I found an anonymous response. Diplomatically titled “Why Carson was an Idiot”, it’s an astute, sarcastic and occasionally quite humorous point-by-point rebuttal (italics are quotes from the Carson article):

Intention of this page here is to correct serious errors in this particular article, which happened due to a serious lack of knowledge about the 109 technics and design history. It begins right here (quotes from the article in “italics”):

“But another household work, the highly propagandized Me-109G, was obsolete when it was built and was aerodynamically the most inefficient fighter of its time. It was a hopeless collection of lumps, bumps, stiff controls, and placed its pilot in a cramped, squarish cockpit with poor visibility.”

The nameless author, who does not appear to be a native English speaker, follows up this opening shot with some fairly devastating comparisons of Carson’s quotes to data on competitive planes, especially the Spitfire.


Fun Videos and Funky Weather

Posted in Aircraft and Flying, Entertainment, Miscellaneous, Social Life by Stacy McMahon on January 15, 2007

I found these gems while staying indoors with the blinds closed yesterday (this was the morning after a party, so you can guess why)

Doing an outside loop in a small plane (zero-g simulation) but someone forgot to warn one of the passengers!

Flying Stuart Little-style. This has to be in the top ten coolest things in the world:

And speaking of R/C aircraft …well, just click:

I felt quite a bit better today, but my plans were scotched due to teh gf being sick, so I decided to open the windows, go outside* and enjoy the weather instead. Yes, in mid-January I am walking around outdoors in shorts and a t-shirt. Also, the neighborhood across Four Mile Run (once you get past the ugly apartments along the highway) is absolutely gorgeous and I am going to start keeping track of real estate over there. It’s all 40s-era bungalows, most of which have nice-looking additions or in some cases teardown replacements. Unlike some of the painfully-chic older neighborhoods in the DC area, this one simply looks lived-in and loved. Now I love it too!

* No, I did not go outside through the windows.

Ugly Betty and Small Aircraft

Posted in Aircraft and Flying, Entertainment by Stacy McMahon on January 11, 2007

This afternoon I was pondering the idea of designing a single-seat airplane around a BMW ‘R’ motor. This is the classic 2-cylinder “boxer” motor that is to BMW motorcycles as the v-twin is to Harley-Davidsons. I figured the way to go would be to base it loosely on the BD-5, but with a modern carbon-fiber monocoque instead of the aluminum stressed-skin fuselage. I wondered how light it could be, keeping mind that an F1 race car’s CF “tub” weighs under 200 lbs and is designed to stand up to a 200-mph meeting with the wall. Turns out the 1960s-vintage BD-5 weighed just under 400 lbs empty, so a CF version could probably come in around 300. Of course this is all academic, but it’s fun to dream.

And, who knew America Ferrera had a new show? She’s traded her trademark curves for braces and hipster-frame glasses in Ugly Betty. Sort of a SoCal version of Just Shoot Me, and not bad!

And Speaking of Flying…

Posted in Aircraft and Flying by Stacy McMahon on September 22, 2006

Getting a private pilot’s license has always been “on my list”. My dad had his when he was about my age, and flew my mom around on some of their dates. I know I’d love it. I’ve always had a natural feel for what makes airplanes tick, and natural talent at handling any vehicle I’ve ever tried, from bikes to powerboats.

So when one of my relatives last weekend was complaining about airport security, and declaring that if she ever flew again she’d be her own pilot, it made me start thinking about small planes again. I’m a compulsive researcher (just ask my friends; one of the most common complaints about me is my know-it-all tendencies) and set off to find out what kind of small airplanes (lightplanes) are available today. Answer: the majority are disappointingly the same as when I was a kid looking through my dad’s old flying stuff.

The few new-age designs out there have specs that tell me something about their designers’ intent. For example, the useful load (weight capacity, incl. fuel) of a Piper Saratoga and a Lancair IV are within 100 lbs or so, but the Lancair cruises almost twice as fast and is 20%+ more fuel-efficient. If you compare any two old and new designs with similar seating capacities, you’ll find about the same thing. New airplanes carry the same load as old ones, but generally faster and with lower fuel consumption–using the same Continental or Lycoming engines.

That’s a whole box of cookies for modern aerodynamics and materials science, but it leaves me scratching my head in one way. The two aircraft linked above, which are fairly typical, have a max load of about 1200 lbs including up to 60-70 gallons of fuel. At a little over 6 lbs/gallon, that’s 400 lbs or so out of that 1200, leaving 800 to divide among pilot, passengers and luggage. Even 6-seat lightplanes come with numbers like that, so unless I’m missing something pretty much every single-engine lightplane on the market can’t fill all its seats without being gigantically overloaded!